Popper starts with a base generator ASP program whose models correspond to hypotheses (definite programs).
Popper augments this generator program with ASP constraints to eliminate models and thus prune hypotheses.
In the generate stage (line 5), Popper uses Clingo [1]}, an ASP system, to search for a model (a hypothesis) of the generator program.
A constraint ensures that the hypothesis has exactly m literals.
If a model is found, Popper converts it to a hypothesis (h).
Otherwise; Popper increments the hypothesis size (line 7) and loops again.
